By John S. McClenahen After today's flood of economic data -- retail sales, CPI, housing starts, and industrial production -- there doesn't seem to be much important stuff that's yet to appear. However, tomorrow morning at 8:30 a.m. EDT, the U.S. Commerce Dept. reports foreign trade numbers for February. And at 10 a.m., the New York-based Conference Board, a business-research group, reports its index of leading economic indicators. The U.S. trade deficit for February will likely be $33.5 billion, with a services surplus of $6.2 billion partially offsetting a manufactured goods deficit of $39.7 billion, figures UBS Warburg LLC, New York. It believes the leading indicators probably continued to decline in March -- 0.3% compared with February-with declining stock prices, higher initial claims for unemployment insurance, and fewer building permits pulling the index down.